The invention concerns a thermal insulation jacket for a gun barrel, especially a cannon barrel, where the thermal insulation jacket consists of a metal jacket that surrounds the gun barrel.
Gun barrels, especially long, slender cannon barrels, undergo bending when temperature differences are present on the surface, and this can result in loss of firing accuracy. Temperature differences on the surface can arise, for example, if the sun is shining on one side of the cold gun barrel or a cold wind is blowing against one side of a hot barrel.
To avoid corresponding uneven heating of the gun barrel, it is known, for example, from DE 19 18 422 A, that the gun barrel can be provided with a thermal insulation jacket, which consists basically of a metal jacket that surrounds the gun barrel with a slight amount of separation from it. The static layer of air between the barrel and the metal jacket serves as a heat insulator.
However, as has been discovered, air convection develops between the surface of the barrel and the metal jacket in a gun barrel that is fired hot, and this air convection causes the underside of the gun barrel to cool more strongly than the upper side of the barrel. These temperature differences lead to undesired barrel distortion, which requires complicated compensation by the gun crew operating the gun.